1. Field of the Invention
The present invention relates to a novel block copolymer and a method of producing the same. More particularly, it relates to a polyamide/polybutadiene/acrylonitrile block copolymer which can be crosslinked and to a method of producing the same.
2. Description of Related Arts
It has been known that polybutadienes have flexible molecular structures and polybutadiene based block copolymers whose representative example is styrene/butadiene block copolymer are excellent thermoplastic elastic material. However, there is a problem that polystyrene chain in the block copolymer has a low softening point and in the case where the block copolymer is used at relatively high temperatures and in some other cases, it does not show satisfactory performance. In order to solve the problem there has been proposed a polyamide/polybutadiene based block copolymer (cf. Japanese Patent Publication (Kokai) No. 60-4 9026 and Japanese Patent Publication (Kokoku) No. 62-3171).
However, the polyamide/polybutadiene based block copolymers proposed heretofore have poor solubility in solvents and poor compatibility with other polymers although they are thermoplastic elastic materials having high heat resistance.